Deglazing cylinders?

[spark2]

Hi all, I have a RK Tek Drop in kit coming for my 2012 800 RMK , with 700 miles on. What is everybody using to Deglaze there Cylinders with? Scotchbrite, or Dingle berry 180 grit .Thanks

 

[xc6rider]

Alot of guys will use a tri-hone or similar now days, but I still prefer using dingleberry type hones. I'm pretty sure 180 is the grit of the ball hone I use (but i'd have to verify that)

I like the quantity of oil the ball hones hold, during the process.

 

[beamslayer]

I use a 3 blade alum oxide 240 grit hone. Not a big fan of ball hones on 2 stoke because of the ports I do use them on 4 stroke tho.

 

[04proxr800]

Don't deglaze it... take the carbon ring of the top with a scotch bright and some contact cleaner.

Anything you used like sand paper, stone hone or scotch bright will deposit dirt in the pores of the nik and remove its ability to hold oil. I just did mine, all I did was clean clean and clean it with wd40 and contact cleaner, oiled it and put it together. 140 psi per side speaks for itself!

 

[04proxr800]

those blade hones and ball hones will just break off in the ports and mess something up!!!

 

[beamslayer]

Wash cylinders with simple green and hot water or dawn dish soap than wipe out with atf and a white cotton rag .

 

[04proxr800]

yes.... white rag, it will tell you when its clean! don't stop till it is, dirt will damage the motor!

 

[rotax]

I see 1 guy saying not to/no need to 'deglaze/hone' the cylinder, others are.

Is the deglazing required/suggested for a rebuild? The instructions I have don't make any mention of it directly.

Thanks.

 

[Mech Engr]

Nickel silicon carbide or Nikasil was developed back in the late 60's by Mahle (Porsche) for some experimental rotary type engines (apex seals) and mostly for Porsche's race program. Once the nickel is mostly gone, within a few hours of engine operation, the compound that's left is silicon carbide which is an extremely hard ceramic. I learned very early on from my Porsche restoration days that the standard alumina (aluminum oxide) hones don't do anything to the Nikasil and as stated before with a two stroke you run the risk of messing up your ports. It takes a diamond hone, which you can buy, to cut through the Nikasil . This is what Porsche reccomends and uses still on their race teams. If you're not going to use a diamond hone then you're better off using nothing at all except to clean it real well before reassembly as suggested in previous posts. When I did the top end on my RMK 900 which also has Niki's, I borrowed a diamond hone from a racer friend of mine. He reccomended chamfering the ports first (like you would after a bore or hone on a normal cylinder). His line of thinking was that it will lesson the chance of the balls getting stuck in the ports. I did mine that way and it turned out great.

John

 

[Mech Engr]

One thing I forgot to add...

The Nikasil coating is electroplated and pretty thin. That means you get in and get out with the diamond hone or you can go through the coating. I did under 10 strokes in/out of the cylinder and that was plenty to get a cross-hatch. I also used a light oil, Triflow.

John

 

[xc6rider]

You would be 100% correct about the Nikasil. However, after prolonged use, the linings can develop a "glaze" buildup, on top of the nikasil lining.

Removing this glaze, is exactly what deglaze honing is for. And if not done, the rings will not seat properly against a clean bore. They might hold compression fine, especially while cold, but once warm and after break-in, the rings will lose seal against the glaze. Aluminum oxide hones work VERY well for this process, with less chance of cutting into or through the nikasil.

I always deglaze, and will continue to on nikasil cylinders.

I highly recommend it, others may not... Youre guys call.